I used to use the Scrapbook plugin for Firefox but I realized for the most part just plaintext might be best. So I'm in the process of setting up a workflow that will save article in markdown in one click and sync between my phone and my computer.
It might be a good compromise between PDF and plain text. It's pretty nice because it essentially serialises a snapshot of the current DOM tree, so it works with all kinds of JS-generated pages.
The files should be relatively grep-able, because it's normal HTML. Of course, you might want to strip HTML tags for more sophisticated searching.
(Seems like a bug in Firefox to me.. maybe this should be a config option..)
https://images.macrumors.com/t/zbOsBhKGQj6VvA9oq8KaZkLxXUc=/...
(note the scrollable preview at right edge of screen, the main preview is only showing a small fraction of the document)
There shouldn't be a need to setup a process. This functionality exists in many places.
For example, I use Joplin to save articles in Markdown format. It's the best web to markdown conversion tool I have found. Then at some point later, I'll pick what's still interesting to me and export from Joplin to PDF if I like.
Insapaper is $3 / month and is a save for later tool. You can then export all your articles in Epub and other formats.
I'm sure there are loads others.